Multisection valve and housing therefor

ABSTRACT

A valve mechanism has a single bushing and spool containing a plurality of separate valve functions. Each valve function is a section angularly spaced from other valve function sections in the same longitudinal region of the bushing and spool.

United States Patent Oct. 17, 1972 Evans [54] MULTISECTION VALVE ANDHOUSING THEREFOR [72] Inventor: Wendell 1. Evans, Cincinnati, Ohio [73]Assignee: Cincinnati Milacron lnc., Cincinnati, Ohio [22] Filed: March15, 197i [2|] Appl. No.: 124,164

[52] U.S. CI. ....l37/625.18, l37/625.25, l37l625.69 [51] int. Cl..Fl6|t 11/07 [58] Field of Search ..l37/625.l8, 625.25, 625.26,137162527, 625.67, 625.68, 625.69

[56] References Cited UNITED STATES PATENTS 990,304 4/l9ll Skinner..l37l625.67

Haberland l 37/625.68 Latham, Jr. l 37/625.67

Primary Examiner-William R. Cline Attorney-Howard T. Kaiser and Jack J.Earl [57] ABSTRACT 4 Claims, 7 Drawing Figures PATENTEDHBT 17 I9723.698.435

sun-:1 1 [IF 2 INVENTOR. WENDELL I. EVANS BACKGROUND OF THE INVENTION Itis often desirable to have hydraulic control valves mechanicallyoperating in tandem while maintaining hydraulic isolation. In the past,this has been done by rigidly connecting a plurality of control valvespools in series. Thus, when the first valve spool is moved all spoolsso connected move in tandem with it. The major drawbacks of this deviceare the increased space requirements necessary to house tandem valvesrather than one single unit, the amount of external piping necessary toprovide supply and exhaust lines for each separate valve, the amount offorce necessary to move the spools so connected in tandem, and thedilficulty in maintaining synchronization of the valves.

The present invention comprises an apparatus which permits enclosure oftandem control valves in a valve mechanism which requires no more spacethan a single control valve of the prior art, yet hydraulically isolatesthe valves.

Another feature of this invention is that once the tandem valves areproperly assembled they cannot become unsynchronized because there isonly a single spool and bushing.

This invention further provides an apparatus which permits directedfluid flow to a number of tandem valve units with a reduction in theamount of necessary tubmg.

The present invention also provides a valve spool which is no largerthan a typical single control valve spool and therefore reduces theforce necessary to move such a spool to that required for the operationof a single control valve.

The valve mechanism of the present invention con sists of a cylindricalbushing that has a number of integral passages for directing fluid tovarious therein. These integral passages replace external tubing oftennecessary in tandem valve arrangements.

The valve spool is separated by lands into a number of isolatedchannels. Circumferential lands separate the valve spool into separatelongitudinal sections which are separated into angularly spaced channelsby longitudinal lands.

When inserted in the bushing the valve spool and bushing are kept inangular orientation by a securing means that prevents rotation of thespool relative to the bushing.

Through use of predetermined flow pathways and ports which are integralwith the spool and the bushing a number of separate hydraulic valvefunctions are provided.

Other advantages and features of the invention will be apparent in theaccompanying drawings and description.

THE DRAWINGS FIG. I is a schematic diagram of a hydraulic servosystemutilizing a set of tandem valves units.

FIG. 2 is an elevational view of the valve bushing of this inventionshowing the portion conforming to one of the tandem valve units of FIG.1.

FIG. 3 is an elevational view of the valve bushing showing a portion 90degrees displaced from the view of FIG. 2 as indicated by arrow 3 inFIG. 2, this portion conforming to the other of the tandem valve unitsof FIG. 1.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2 showing thespool portion conforming to the same tandem valve unit as the bushing inFIG. 2.

FIG. 5 is a sectional view taken along line 5--5 of FIG. 3 showing thespool portion conforming to the same tandem valve unit as the bushing inFIG. 3.

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 2.

FIG. 7 is a perspective view of the spool.

DESCRIPTION FIG. 1 illustrates a hydraulic servo-system utilizing atandem valve arrangement. The system is more fully described intheco-pending application of the present inventor, entitled "Variable GainAmplifier for Hydraulic Servo-System", filed Mar. I5, I97 I Ser. No.124, 165, and assigned to the assignee of the present application.

An input 10 is supplied to a motor II which rotates the shaft 12 eitherclockwise or counter-clockwise. The circular wobble plate 13 is securedat its center to the shaft 12. As the shaft 12 rotates, the wobble plate13 displaces rod 14 of valve spool 15.

Valve spools l5 and 16 are mechanically connected in tandem by connector17. The connector 17 is rigidly secured to ends 18 and 19 of spools l5and I6, respectively. Control valves 20 and 21, therefore, must operatemechanically in tandem.

On supply pump 22 supplies fluid flow toboth control valves 20 and 21-.The exhaust system 23 for valve 20 is isolated from the exhaust system24 of valve 21 for purposes of illustration. However, in the describedapparatus the exhaust systems 23 and 24 could be integrated. Reservoir25 serves as an exhaust drain and a fluid source for pump 22.

Spools 15 and 16 are both illustrated at null. As wob ble plate 13rotates, the spools l5 and 16 will be displaced. Assuming displacementto the left, pressure ports 45 and 52 will then be open to chambers 81and 75, respectively. Control line 28 will then supply fluid underpressure to chamber 41 of slide cylinder 36. Control line 30 of valve 21likewise becomes a supply line, supplying fluid to hydraulic intensifier35. This pushes plunger 37 down and injects a shot of fluid into line 32which increases the pressure of the fluid in chamber 41 in the mannerdescribed in the afore-rnentioned co-pending application.

Piston 40 is moved out and table 38 is moved to the position called forby input 10. The fluid in chamber 42 now must be evacuated throughexhaust lines 29 and 33. Exhaust line 29 directs fluid to chamber 82 ofvalve 20, which is open to the exhaust system 23 through port 48.Exhaust line 33 directs fluid to chamber of hydraulic intensifier 3!.This pushes plunger 101 up and forces fluid in chamber 102 into line 31.Line 31 is open to exhaust system 24 through port 55 in chamber 76 ofvalve 21.

Thus, it can be seen that the valves 20 and 21 must operate in tandem inthe present application.

Now turning to FIGS. 2 and 3, the two tandem valves 20 and 21 can behoused in the same longitudinal section of a single cylindrical bushing57. The spool 83, illustrated in FIG. 7, controls the same functions asboth spools l5 and 16 ofFlG. l.

In FIG. 2, the portion of the bushing 51 which'is vigi ble correspondsto the control valve 20 of FIG. 1. The portion visible in FIG. 3 whichis a view displaced 90 from FIG. 1, as indicated by sight arrow 3 ofFIG. 1, corresponds to valve 21. The housing 58 provides isolation ofthe channels of bushing 57 as will be apparent from the description.Since the same supply system is used for both valves 20. and 21 only onesupply line 97 need be provided in the bushing 57, instead of two, lines26 and 27, as before By providing circumferential channel 86 around theentire periphery of bushing 57 one fluid supply passage 97 supplies allpressure ports 45, 46, 52 and 53.

Exhaust ports 48 and 49 are isolated from exhaust ports 55 and 56. Itshould be noted that ports 48 and 49, and ports 55 and 56, could beconnected in the fashion similar to that used in joining the pressureports 45, 46, 52 and 53 by using a channel identical to channel 86 ifisolation is not desired.

A circumferential channel 84 exists around at least half but not all ofthe periphery of bushing 57, connecting the diametrically opposed ports48 and 49, as best seen in FlGs. 2 and 4. To isolate the ports 55 and56, which are also diametrically opposed but displaced 90, from ports 48and 49 internal channeling must be utilized. In FIG. is shown a hole 93drilled in bushing 57 to port 55. The hole 93 is then plugged by plug93a. The channel 89 extends around the entire periphery of bushing 57. Ahole 94 is drilled into hole 93, connecting port 55 with channel 89. Thediametrically opposite port 56 can be connected to circumferentialchannel 89 by longitudinal external channel 91 as shown best in FIGS. 3and 5. The diametrically opposite exhaust ports 55 and 56 are thusconnected to each other but isolated from exhaust ports 48 and 49.Exhaust ports 43 and 44 are isolated from exhaust ports 50 and 51 in thesame fashion.

As seen in FIG. 3, all exhaust ports 43, 44, 48, 49, 50, 51, 55 and 56could be joined simply by continuing channels 84 and 88 around theexternal circumference of bushing 57 and drilling a hole 65 as indicatedin phantom, allowing fluid flow from channel 84 to channel 88 withoutany external piping.

Control ports 63 and 64 may also be isolated. in FIG. 4, thediametrically opposite ports 63 are connected by channel 87 which hasthe same configuration of channels 84 and 88. Diametrically oppositecontrol ports 47 are connected in the same fashion by channel 85.

As shown in FIG. 5 only a single port 63 is utilized in the illustratedembodiment of the invention. Therefore, no channeling in bushing 57 isnecessary.

The spool 83, shown in perspective in FIG. 7, also must be of uniqueconstruction to provide a plurality of valves in a single mechanism.instead of the land and cannelure configuration illustrated in spools l5and 16, spool 83 consists of isolated channels. The circumferentiallands 72, 73 and 74 are the same as the lands of spool and 16. Thelongitudinal lands 98 and 99, however, separate the cannelures of atypical spool into isolated channels 75 through 82. Channels 79, 80, 81and 82 correspond to the cannelure of spool 15, and channels 75, 76, 77and 78 correspond to the cannulures of spool 16. Thus both valves [5 and16 are contained in the same longitudinal region of the valve mechanismof the present invention.

As herein described, and illustrated in FIG. 5 only a single controlport 59 is provided in the valve mechanism of the preferred embodiment.The section view illustrated in FIG. 6 is cut through bushing 57 andspool 83 to better illustrate the use of single porting in the valvemechanism. To maintain hydraulic balance within the spool fluid must bepresent in both of diametrically opposite channels 76 and 77. A hole 71is drilled through spool 83 communicating these channels. Thus hydraulicbalance is maintained in the valve mechanism as herein described, eventhrough external channeling is not used. It can be seen in FIG. 5 thatport 63 communicating with channels 75 and 78 in the same manner throughhole 70.

Spool 83 is inserted in the bore of bushing 57 to form a plurality ofvalves angularly spaced in the same longitudinal region of the spool andbushing. The spool 83 must not rotate in bushing 57 when used in thismanner. For this purpose a hole 61 is provided in spool 83 in which isinserted and secured a pin 60. Pin 60 slides in hole 62 of housing 58thus keeping spool 83 in rotational orientation while permittingmovement along its longitudinal axis.

if desired, more than two valves could be housed in the apparatus asherein described. The diametrically opposite channels of spool 83 couldbe isolated from each other by alternate channeling of fluid flow in thebushing 57 or by eliminating holes and 71.

it can be seen that as many as four valves could be housed in thepreferred embodiment of the present invention. It should further beunderstood that the embodiment of invention as herein described isillustrative only and the invention includes all all alterations andmodifications within the scope of the appended claims.

What is claimed is:

l. A valve mechanism having a cylindrical bushing with a boretherethrough, a spool inserted in said bore, said spool comprising aplurality of valve function sections, and said valve mechanism beingsuited to receive hydraulic fluid under pressure for directing flow tovarious elements of an hydraulic circuit, said valve mechanismcomprising:

a means for providing a plurality of separate valve function sectionsspaced angularly about the circumference of said cylindrical bushing;

b. means associated with said bushing for providing isolated flowpathways through the separate valve function sections;

c. means associated with said spool for isolating said function sectionsfrom one another to maintain independent circuit utility, wherebyindependent valve functions are controlled by movement of said spoolrelative to said bushing; and

cl. means for maintaining the angular displacement of the spool relativeto the bushing.

2. The apparatus of claim 1 wherein said valve mechanism furthercomprises means for providing separate valve function sections spacedlongitudinally along the axis of said cylindrical bushing.

3. The apparatus of claim I wherein said means associated with saidbushing further comprises:

a. one set of diametrically opposite ports whereby hydraulic fluid isintroduced into the bore of said cylindrical bushing;

4. The apparatus of claim 1 wherein said spool further comprises:

a. one set of diametrically opposite channels for controlling the rateof fluid flow through the fore to the ports in said bushing;

b. another set of diametrically opposite channels which are angularlydisplaced from said one set of diametrically opposite channels and atsubstantially the same longitudinal position in the spool whereby theflow rate of hydraulic fluid through the bore and bushing is controlled;and

. means for communicating selected channels of the valve spool, wherebyhydraulic fluid flow is maintained through the cylindrical bore of thebushing in a preselected manner.

* 1 It i l

1. A valve mechanism having a cylindrical bushing with a boretherethrough, a spool inserted in said bore, said spool comprising aplurality of valve function sections, and said valve mechanism beingsuited to receive hydraulic fluid under pressure for directing flow tovarious elements of an hydraulic circuit, said valve mechanismcomprising: a. means for providing a plurality of separate valvefunction sections spaced angularly about the circumference of saidcylindrical bushing; b. means associated with said bushing for providingisolated flow pathways through the separate valve function sections; c.means associated with said spool for isolating said function sectionsfrom one another to maintain independent circuit utility, wherebyindependent valve functions are controlled by movement of said spoolrelative to said bushing; and d. means for maintaining the angulardisplacement of the spool relative to the bushing.
 2. The apparatus ofclaim 1 wherein said valve mechanism further comprises means forproviding separate valve function sections spaced longitudinally alongthe axis of said cylindrical bushing.
 3. The apparatus of claim 1wherein said means associated with said bushing further comprises: a.one set of diametrically opposite ports whereby hydraulic fluid isintroduced into the bore of said cylindrical bushing; b. another set ofdiametrically opposite ports which are angularly displaced from said oneset of diametrically opposite ports and contained in substantially thesame longitudinal position in the bushing, whereby hydraulic fluid maybe introduced or removed from the bore in said bushing; c. flow pathwaysintegral within said bushing communicating selective ports with oneanother.
 4. The apparatus of claim 1 wherein said spool furthercomprises: a. one set of diametrically opposite channels for controllingthe rate of fluid flow through the bore to the ports in said bushing; b.another set of diametrically opposite channels which are angularlydisplaced from said one set of diametrically opposite channels and atsubstantially the same longitudinal position in the spool whereby theflow rate of hydraulic fluid through the bore and bushing is controlled;and c. means for communicating selected channels of the valve spool,whereby hydraulic fluid flow is maintained through the cylindrical boreof the bushing in a preselected manner.